A shorthand notation is used to represent sums with more than a few
terms. This shorthand notation uses the Greek letter sigma
(which denotes sum). If we have a rule such as f (n)
which assigns the value f (n) to each integer n
in the set of integers {j,j+1, j+2, ... k},
we can represent the sum as: =

On the graphing calculator:

We will be using the sum feature and the seq feature to work with a general
summation.
On the
calculator, we will interpret a summation as follows:

2nd
STAT (LIST) → MATH
#5 sumThe format for sum
is sum( list )where
list will be the terms of
the rule.

While sequences have a domain of
natural numbers, {1, 2, 3, 4, ...}, in Func
mode, the sequence command will
accept integer domain values less than one. (In Seq mode, however, the sequence command will accept only
integer domain values of 1 or greater.)

Example 1:
Evaluate: notice that this sum starts
with k = 2

Example 2:
Evaluate:

(For ease of entry, X
was used as the variable in both examples above.
If you wish to use the designated variable, type it into the
calculator using the alpha
key.)

If
you think you are going to forget these commands:

Another approach to
Example 1:
Type the number of terms needed into L1.
Type the rule into
L2.
Add the answers manually on the HOME
screen.

Or, have the calculator do the
adding. If you do not want to add manually on the home
screen, you can use the cumulative
summation feature (cumSum) to add L2.Remember that Example 1 starts with k = 2.